Accepted Answer TL;DR:<p>[sorry]
we will not charge for development that happens under the “App Explore” product (i.e., the free version). Usage of the Appcelerator platform (Titanium Mobile SDK, Titanium Studio, Analytics and Cloud Services) at this level is permitted for all applications, both commercial and free, with no financial obligation to Appcelerator.
[sorry, we aren't transparent enough]